JP5148886B2 - Soluble polyfunctional vinyl aromatic copolymer having phenolic hydroxyl group at its terminal and method for producing the same - Google Patents

Description

  The present invention relates to a soluble polyfunctional vinyl aromatic polymer having a phenolic hydroxyl group at its terminal and a method for producing the same.

  Many of the monomers having a reactively active unsaturated bond can generate a polymer by selecting a catalyst and an appropriate reaction condition in which the unsaturated bond is cleaved to cause a chain reaction. As a general-purpose monomer representing such a monomer having an unsaturated bond, vinyl aromatic compounds such as styrene, alkylstyrene and alkoxystyrene can be exemplified. A wide variety of resins have been synthesized by using such vinyl aromatic compounds alone or by copolymerizing them.

  However, the applications of polymers obtained from such vinyl aromatic compounds are mainly limited to the field of relatively inexpensive consumer equipment, and are highly functional and advanced like printed wiring boards in the electrical and electronic fields. There is almost no application to advanced technology that requires thermal and mechanical properties. The reason is that thermal characteristics such as heat resistance or heat decomposability and workability such as solvent solubility or film formability cannot be satisfied at the same time.

  As a method for solving the disadvantages of the conventional vinyl aromatic polymer, Patent Document 1 discloses divinyl aromatic compound (a) and monovinyl aromatic compound (b) in an organic solvent, Lewis acid catalyst and specific structure. A soluble polyfunctional vinyl aromatic copolymer obtained by polymerizing at a temperature of 20 to 100 ° C. in the presence of an initiator is disclosed. Patent Document 2 discloses a monomer component comprising 20 to 100 mol% of a divinyl aromatic compound (a) in the presence of a quaternary ammonium salt, using a Lewis acid catalyst and an initiator having a specific structure. A method for producing a soluble polyfunctional vinyl aromatic copolymer having a controlled molecular weight distribution by cationic polymerization at a temperature of ˜120 ° C. is disclosed. The soluble polyfunctional vinyl aromatic copolymer obtained by the techniques disclosed in these two patents is excellent in solvent solubility and processability, and by using this, a cured product having a high glass transition temperature and excellent heat resistance can be obtained. Can be obtained. However, although the soluble polyfunctional vinyl aromatic copolymer obtained by these techniques can be said to be a polymer having excellent heat resistance in terms of giving a cured product having a high glass transition temperature, From the viewpoint of generation of gas and outgas, the thermal decomposition resistance to high process temperatures corresponding to recent lead-free solder is not sufficient, and there are cases where defects such as blistering and discoloration occur due to a high thermal history around 300 ° C. It was. Furthermore, since the soluble polyfunctional vinyl aromatic copolymer obtained by these techniques does not have a polar group that gives adhesion to metal, there is a problem that adhesion to metal wiring is not sufficient. Was.

  On the other hand, in Patent Document 3, by performing living cationic polymerization at a low temperature in the presence of a halogen-containing organic compound having a specific structure that acts as a chain transfer agent and a cationically polymerizable monomer containing isobutylene, and a Lewis acid. Synthesize an isobutylene polymer having an isobutylyl group at the terminal, and further, in the presence of a Lewis acid, perform a Friedel-Crafts-type reaction between the isobutylene polymer having an isobutylene group at the terminal and a phenol compound having a specific structure. Discloses a method for producing an isobutylene polymer having a hydroxyl group at the terminal end. However, the isobutylene polymer having isobutylene at the end synthesized by this technique does not have a pendant vinyl group due to the fact that no polyfunctional vinyl aromatic compound is used. The glass transition temperature is low, and there is a problem that it cannot be applied to advanced technology fields that require high performance and high thermal and mechanical properties such as electrical and electronic fields. Moreover, in order to introduce 1.1 or more functional groups per molecule at the end, it was necessary to use a polyfunctional special compound as an initiator.

  Therefore, it solves the various problems of the above-mentioned prior art, has excellent heat resistance and heat decomposition resistance even for a high heat history, has a vinyl group with excellent curability in the pendant position, and has adhesive properties. There has never been a polyfunctional vinyl aromatic copolymer having a functional group capable of imparting a function such as a terminal and having a controlled molecular weight distribution and solvent solubility excellent in molding processability.

JP 2004-123873 A Japanese Patent Laid-Open No. 2005-213443 JP-A-4-20501

  The present invention has excellent heat resistance against a high heat history, has a pendant vinyl group with excellent curability, has a controlled low molecular weight excellent in processability and solvent solubility, and is bonded to the end. It is an object of the present invention to provide a polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group capable of imparting a function such as functionality and a production method for producing the copolymer with high efficiency.

（式中、Ｒ¹は炭素数６〜３０の芳香族炭化水素基を示す。）で表される未反応のビニル基を含有する構造単位の含有量が１０〜９０モル％であることを特徴とする末端にフェノール性水酸基を有する可溶性多官能ビニル芳香族共重合体である。 The present invention relates to a copolymer obtained by copolymerizing 20 to 99 mol% of a divinyl aromatic compound (a) and 80 to 1 mol% of a monovinyl aromatic compound (b), and is polymerized at a part of its terminals. The following formula (a1) having a phenolic hydroxyl group derived from the additive (c) and derived from the divinyl aromatic compound (a)

(In the formula, R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms.) The content of the structural unit containing an unreacted vinyl group is 10 to 90 mol%. It is a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal.

  This soluble polyfunctional vinyl aromatic copolymer has a number average molecular weight Mn of 500 to 100,000, and a molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is 10.0 or less. It is preferable that Moreover, it is preferable that the introduction amount (a1) to the terminal of the phenolic hydroxyl group is 2.2 / molecule or more.

The present invention also provides:
(A) Lewis acid catalyst (B) One or more promoters selected from ester compounds (C) In the presence of one or more polymerization additives selected from phenolic compounds, divinyl aromatic compounds are added in an amount of 20 to 99 mol% and A monomer component containing 80 to 1 mol% of a monovinyl aromatic compound is polymerized at a temperature of 20 to 120 ° C. in a homogeneous solvent dissolved in a solvent having a dielectric constant of 2.0 to 15.0. This is a method for producing the above-mentioned soluble polyfunctional vinyl aromatic copolymer.

  Here, the Lewis acid catalyst is preferably a metal fluoride or a complex thereof. As the co-catalyst, one or more ester compounds selected from the group consisting of ethyl acetate, propyl acetate and butyl acetate are preferable. As the polymerization additive, a phenol compound having one or more phenolic hydroxyl groups selected from the group consisting of phenol, alkylphenol, dialkylphenol, phenylphenol, alkylphenylphenol, naphthol and alkylnaphthol is preferable.

  Hereinafter, the soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal of the present invention (hereinafter also referred to as the copolymer of the present invention) and the production method thereof will be described in detail.

  The copolymer of the present invention is a copolymer obtained by copolymerizing a divinyl aromatic compound and a monovinyl aromatic compound, having a phenolic hydroxyl group in a part of its end groups, and a divinyl aromatic A soluble polyfunctional vinyl aromatic having a phenolic hydroxyl group at the terminal, the content of the structural unit containing an unreacted vinyl group represented by the above formula (a1) derived from the compound (a) being 10 to 90 mol% It is a copolymer. Here, soluble means that it is soluble in toluene, xylene, tetrahydrofuran, dichloroethane or chloroform.

  Since the copolymer of the present invention is obtained by copolymerizing a monomer containing a divinyl aromatic compound, it has a branched structure or a crosslinked structure, but the abundance of such a structure is limited to the extent that it is soluble. Is done. Therefore, it is a polyfunctional vinyl aromatic copolymer having a certain amount of structural units containing an unreacted vinyl group represented by the above formula (a1). The unreacted vinyl group in the structural unit represented by the formula (a1) is also referred to as a pendant vinyl group, and since this exhibits polymerizability, it can be polymerized by further polymerization treatment to give a solvent-insoluble thermosetting resin. it can. Furthermore, the copolymer of the present invention has a phenolic hydroxyl group derived from the polymerization additive at the terminal. And since the copolymer which does not have a phenolic hydroxyl group at the terminal, and its manufacturing method are well-known in the said patent document 1, 2, etc., they are understood by referring those description.

  The copolymer of the present invention has a phenolic hydroxyl group at a part of the terminal of the polymer, and the amount of the phenolic hydroxyl group at the terminal is 2.2 (pieces / molecule) or more. Is preferred. More preferably, it is 2.5 (pieces / molecule) or more, and particularly preferably 3.0 (pieces / molecule) or more. By introducing a phenolic hydroxyl group into the terminal of the copolymer of the present invention, a molded article with improved adhesion can be obtained. The upper limit of the amount of the terminal phenolic hydroxyl group is not limited, but is preferably 100 (number / molecule) or less, more preferably 20 (number / molecule).

  The copolymer of the present invention is obtained by copolymerizing a pendant vinyl group derived from a divinyl aromatic compound so that a phenolic hydroxyl group is introduced into a part of the terminal. Usually, in the case of a linear polymer obtained by polymerizing a monovinyl aromatic compound, there are two terminals, ie, a start terminal and a terminal terminal, so that in the presence of a phenolic compound as in the present invention, a Lewis acid is used. When a cationic polymerization method using a catalyst is carried out, only one phenolic hydroxyl group enters the terminal end. However, in the soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the end of the present invention, a divinyl aromatic compound is used as a monomer component. A portion of another vinyl group of the incorporated divinyl aromatic compound undergoes a polymerization reaction, resulting in branching in the structure.

  FIG. 1 shows a reaction formula schematically illustrating the branching reaction. When one branch is formed, the terminal ends are 2 in total, 2 start ends and 2 stop ends, and 2 phenolic hydroxyl ends can be included. Thus, according to the present invention, in the polymerization process, the growing polymer chain causes a polymerization reaction to the pendant vinyl portion of another polymer, thereby generating a branch and increasing the number of terminals. This makes it possible to introduce two or more phenolic hydroxyl groups into one molecule.

  The copolymer of the present invention is obtained by copolymerizing 20 to 99 mol% of the divinyl aromatic compound (a) and 1 to 80 mol% of the monovinyl aromatic compound (b). The composition ratio of the monomer has a structural unit derived from the divinyl aromatic compound (a) and a structural unit derived from the monovinyl aromatic compound (b). The copolymer of the present invention preferably contains 25 to 95 mol% of the structural unit derived from the divinyl aromatic compound (a) with respect to the structural unit derived from all monomers. More preferably, it is 30-90 mol%. When the structural unit derived from the divinyl aromatic compound (a) to be used is less than 10 mol%, the heat resistance of the cured product is insufficient, which is not preferable. On the other hand, when the structural unit derived from the divinyl aromatic compound (a) exceeds 99 mol%, the moldability is lowered, which is not preferable.

  The divinyl aromatic compound (a) is important as a crosslinking component for branching or crosslinking the copolymer of the present invention, generating a pendant vinyl group, and exhibiting heat resistance when the copolymer is thermally cured. Play an important role.

  Examples of the divinyl aromatic compound (a) include divinylbenzene (both isomers of m- and p-), divinylnaphthalene (including each isomer), divinylbiphenyl (including each isomer), and the like. However, it is not limited to these. Moreover, these can be used individually or in combination of 2 or more types. In particular, from the viewpoint of cost and availability, divinylbenzene (both isomers of m- and p-), and when higher heat resistance is required, divinylnaphthalene (including each isomer), divinylbiphenyl ( Each isomer is preferred).

Since the structural unit represented by the formula (a1) is derived from the divinyl aromatic compound (a), R ¹ in the formula (a1) can be understood from the divinyl aromatic compound (a). That is, when divinylbenzene is used as the divinyl aromatic compound, R ¹ is a phenylene group, and other divinyl aromatic compounds such as divinylbiphenyl are understood to be residues generated by removing two vinyl groups therefrom. The structural unit generated from the divinyl aromatic compound (a) may be a double bond in the main chain, and is not limited to the structural unit represented by the formula (a1) or the branched structural unit.

  Monovinyl aromatic compound (b) is used with divinyl aromatic compound (a) to improve the solvent solubility and processability of the copolymers of the present invention.

  Examples of monovinyl aromatic compounds (b) include, but are not limited to, styrene, nuclear alkyl substituted monovinyl aromatic compounds, α-alkyl substituted monovinyl aromatic compounds, β-alkyl substituted styrenes, alkoxy substituted styrenes, and the like. It is not a thing. In order to prevent polymer gelation and improve solubility in solvents and processability, especially styrene, ethylvinylbenzene (both isomers of m- and p-), ethylvinylbiphenyl (including each isomer) Is preferred from the viewpoint of cost and availability.

  Further, the copolymer of the present invention is within the range not impairing the effects of the present invention, in addition to the structural unit derived from the monovinyl aromatic compound (a) and the divinyl aromatic compound (b), trivinyl aromatic compound, trivinyl. Structural units derived from other monomer components (c) such as aliphatic compounds, divinyl aliphatic compounds and monovinyl aliphatic compounds can be introduced.

  Specific examples of the other monomer component (c) include 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane, ethylene glycol diester. Examples thereof include, but are not limited to, acrylate and butadiene. These can be used alone or in combination of two or more. The structural unit derived from the other monomer component (c) is within a range of less than 30 mol% with respect to the total amount of the structural unit derived from the monomer component (a) and the structural unit derived from the monomer component (b). Used in.

  The number average molecular weight Mn (wherein Mn is a number average molecular weight in terms of standard polystyrene measured using gel permeation chromatography) of the copolymer of the present invention is preferably 500 to 100,000, more preferably 700 to 50,000. More preferably, it is 1000-20000. If the Mn is less than 500, the viscosity of the soluble polyfunctional vinyl aromatic polymer is too low, so that it becomes difficult to form a thick film, and the workability is lowered. Since it becomes easy to generate | occur | produce and a viscosity becomes high, when it shape | molds to a film etc., since the fall of an external appearance is caused, it is not preferable. The value of molecular weight distribution (Mw / Mn) obtained from Mn and weight average molecular weight Mw is 10.0 or less, preferably 5.0 or less. When Mw / Mn exceeds 10.0, problems such as deterioration of processing characteristics and generation of gel of a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal are caused.

  In the copolymer of the present invention, the above monomer is present in the presence of one or more polymerization additives selected from (A) a Lewis acid catalyst and (B) one or more cocatalysts selected from ester compounds (C) phenolic compounds. It can obtain by carrying out cationic copolymerization under.

  Next, the manufacturing method of this invention is demonstrated. In the production method of the present invention, the divinyl aromatic compound (a) is 20 to 99 mol%, preferably 25 to 95 mol%, more preferably 30 to 90 mol%, and the monovinyl aromatic compound is 80 to 1 mol%. The monomer component containing 75 to 5 mol%, more preferably 70 to 10 mol% is preferably copolymerized. At this time, the other monomer component (c) can be used in an amount of less than 30 mol% as described above.

  The (A) Lewis acid catalyst used in the production method of the present invention is not particularly limited as long as it is a compound composed of a metal ion (acid) and a ligand (base) and can receive an electron pair. Can be used. Among Lewis acid catalysts, from the viewpoint of the thermal decomposition resistance of the copolymer, in particular, B, Al, Ga, In, Si, Ge, Sn, Pb, Sb, Bi, Ti, W, Zn, Fe, V, etc. Hexavalent metal fluoride is preferred. Said catalyst is not specifically limited, It can use individually or in combination of 2 or more types. From the viewpoint of controlling the molecular weight and molecular weight distribution of the copolymer of the present invention and polymerization activity, boron trifluoride ether (diethyl ether, dimethyl ether, etc.) complexes are most preferably used.

  (B) As a co-catalyst, 1 or more types chosen from an ester compound are mentioned. Among them, ester compounds having 4 to 30 carbon atoms are preferably used from the viewpoint of polymerization rate and control of molecular weight distribution of the polymer. From the viewpoint of availability, ethyl acetate, propyl acetate and butyl acetate are preferably used.

  (C) The polymerization additive causes a chain transfer reaction with the polymerization active species during the polymerization reaction, and introduces a phenolic hydroxyl group that enables functionalization such as adhesiveness to the terminal of the copolymer of the present invention. It is a compound that fulfills

  The polymerization additive is not particularly limited as long as it is a phenolic compound, but has a phenolic hydroxyl group having 6 to 30 carbon atoms such as phenol, alkylphenol, dialkylphenol, phenylphenol, alkylphenylphenol, naphthol, and alkylnaphthol. One or more polymerization additives selected from the group consisting of aromatic hydrocarbon compounds can be mentioned. Of these phenol compounds, phenol and 2,6-xylenol are preferably used from the viewpoint of reactivity and availability.

  The Lewis acid catalyst is used in the range of 0.001 to 10 mol, more preferably 0.001 to 0.01 mol, relative to 1 mol of the polymerization additive. When the amount of the Lewis acid catalyst used exceeds 10 moles with respect to 1 mole of the polymerization additive, the polymerization rate becomes too high, so that not only the control of the molecular weight distribution becomes difficult, but also the introduction amount of the phenolic hydroxyl group decreases. Therefore, it is not preferable.

  The cocatalyst is used in the range of 0.001 to 10 mol with respect to 1 mol of the polymerization additive, more preferably 0.01 to 1 mol. When the amount of the cocatalyst used exceeds 10 moles per mole of the polymerization additive, the polymerization rate is decreased, not only the yield of the copolymer is lowered, but also the introduction amount of the phenolic hydroxyl group is preferably reduced. Absent. On the other hand, if the amount of the cocatalyst used is less than 0.001 mol with respect to 1 mol of the polymerization additive, the selectivity of the polymerization reaction decreases, so that the molecular weight distribution increases, the formation of gel, and the polymerization rate increase It becomes difficult to control the polymerization reaction involved.

  The polymerization additive is preferably used in a range of 0.005 to 50 mol, more preferably 0.01 to 10 mol, and particularly preferably with respect to 1 mol in total of all monomers. 0.1 to 5 mol. When the addition amount of the polymerization additive is less than 0.005 mol with respect to 1 mol of the monomer, the introduction amount of the phenolic hydroxyl group is reduced, not only the functions such as adhesiveness are lowered, but also the molecular weight and molecular weight distribution. Increases, and molding processability deteriorates, which is not preferable. In addition, if the amount of the polymerization additive used exceeds 50 moles with respect to 1 mole of the monomer, the content of pendant vinyl groups in the resulting polymer is remarkably reduced, so a cured product obtained by curing the copolymer. Lowers the heat resistance. Moreover, since the molecular weight and molecular weight distribution of the produced | generated copolymer increase, it is unpreferable also from a viewpoint of moldability.

  The polymerization reaction is carried out in one or more solvents having a dielectric constant of 2 to 15 for dissolving the soluble polyfunctional vinyl aromatic copolymer to be produced. As a solvent, an organic compound that does not essentially inhibit cationic polymerization and dissolves a Lewis acid catalyst, a co-catalyst, an initiator, a monomer, and a polyfunctional vinyl aromatic copolymer to form a homogeneous solution. A solvent is good. If a dielectric constant is in the range of 2-15, there will be no restriction | limiting in particular, A solvent can be used individually or in combination of 2 or more types. If the dielectric constant of the solvent is less than 2, it is not preferable because the molecular weight distribution becomes wide, and if it exceeds 15, the gel tends to be formed, which is not preferable.

  From the viewpoint of the balance between polymerization activity and solubility, the solvent is particularly preferably toluene, xylene, n-hexane, cyclohexane, methylcyclohexane or ethylcyclohexane. Further, the amount of the solvent used is such that the concentration of the copolymer in the polymerization solution at the end of the polymerization is 1 to 80 wt%, preferably 5 to 60 wt%, in consideration of the viscosity of the resulting polymerization solution and the ease of heat removal. Particularly preferably, it is determined to be 7 to 50 wt%. When the concentration of the copolymer in the polymerization solution at the end of the polymerization is less than 1 wt%, it is not preferable because the cost is increased due to the low polymerization efficiency. On the other hand, if it exceeds 80 wt%, the molecular weight and the molecular weight distribution increase, which leads to a decrease in molding processability.

  The polymerization temperature is in the range of 20 to 120 ° C, preferably 40 to 100 ° C. When the polymerization temperature exceeds 120 ° C., the selectivity of the reaction decreases, causing problems such as an increase in the molecular weight distribution and the generation of gel, and when the polymerization is carried out at a temperature below 20 ° C., the molecular weight of the resulting copolymer increases. However, this is not preferable because it causes a decrease in moldability.

  The method for recovering the copolymer after the termination of the polymerization reaction is not particularly limited. For example, a commonly used method such as a steam stripping method or precipitation with a poor solvent may be used.

  According to the present invention, it is possible to obtain a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the end with improved adhesion and thermal decomposition resistance, and at the same time, the copolymer can be produced with high efficiency. In addition, the soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal of the present invention can be processed into a molding material, a sheet or a film, and has characteristics such as a low dielectric constant, a low water absorption, and a high heat resistance. Can be applied to printed wiring board-related materials, semiconductor-related materials, or transparent materials for optical devices, and further to paints / inks, photosensitive materials, and adhesives.

  EXAMPLES Next, although an Example demonstrates this invention, this invention is not restrict | limited by these. In addition, all the parts in each example are parts by weight. Moreover, the measurement of the softening temperature etc. in an Example performed sample preparation and a measurement with the method shown below.

1) Molecular weight and molecular weight distribution of copolymer GPC (manufactured by Tosoh Corporation, HLC-8120GPC) was used, tetrahydrofuran was used as a solvent, flow rate was 1.0 ml / min, column temperature was 38 ° C., and a calibration curve using monodisperse polystyrene was used. .

2) Polymer structure It was determined by ¹³ C-NMR and ¹ H-NMR analysis using a JNM-LA600 type nuclear magnetic resonance spectrometer manufactured by JEOL. Using chloroform -d ₁ as a solvent, was used resonance line of tetramethylsilane as an internal standard.

3) Terminal phenolic hydroxyl group The number was calculated from the number average molecular weight obtained from the GPC measurement and the terminal phenolic hydroxyl group obtained from the results of ¹ H-NMR measurement and elemental analysis.

4) Sample preparation and measurement of glass transition temperature (Tg) and softening temperature (Sp) measurement Copolymer solution was uniformly applied to a glass substrate so that the thickness after drying was 20 μm, and a hot plate was used. Heated at 90 minutes for 30 minutes and dried. The resin film obtained together with the glass substrate is set in TMA (thermomechanical analyzer), heated to 220 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream, and further heat-treated at 220 ° C. for 20 minutes. The remaining solvent was removed. After allowing the glass substrate to cool to room temperature, an analytical probe is brought into contact with the sample in the TMA measuring apparatus, and scan measurement is performed from 30 ° C. to 360 ° C. at a temperature rising rate of 10 ° C./min under a nitrogen stream. The softening temperature and glass transition temperature were determined.

5) Evaluation of heat resistance and measurement of heat discoloration The copolymer is set in a TGA (thermobalance) measuring device and measured by scanning from 30 ° C to 320 ° C at a temperature rising rate of 10 ° C / min under a nitrogen stream. By determining the weight loss at 300 ° C. as heat resistance and visually confirming the amount of discoloration of the sample after measurement, and classifying it as A: no thermal discoloration, B: pale yellow, C: brown, D: black The heat discoloration was evaluated.

6) Measurement of total light transmittance The copolymer was set in a turbidimeter measuring device and measured by applying halogen light.

  4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 158 g (1.8 mol) of ethyl acetate, 1649 g (13.5 g) of 2,6-xylenol Mol) and 12745 g of toluene were charged into a 30 L reactor, and 18 g (120 mmol) of diethyl ether complex of boron trifluoride was added at 70 ° C. and reacted for 2 hours. After the polymerization solution was stopped with 53.3 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a copolymer. The obtained copolymer was washed with n-hexane, filtered, dried and weighed to obtain 3948 g of copolymer A (yield: 70.9 wt%).

Mn of the obtained copolymer A was 2820, Mw was 10800, and Mw / Mn was 3.84. By performing ¹³ C-NMR and ¹ H-NMR analyses, resonance lines derived from the 2,6-xylenol end of copolymer A were observed. As a result of conducting an elemental analysis result of the copolymer A, it was C: 88.2 wt%, H: 7.9 wt%, and O: 3.3 wt%. The introduction amount (a) of phenolic hydroxyl groups in the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 5.8 (pieces / molecule). Further, it contained 79.2 mol% of structural units derived from divinylbenzene and 20.7 mol% in total of structural units derived from styrene and ethylbenzene. The vinyl group content contained in the copolymer A was 32 mol%. As a result of the TMA measurement, Tg was 275 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 1.5 wt%, and the heat discoloration was A. Copolymer A was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed.

Polyfunctional vinyl aromatic copolymer A obtained in Example 1: 4.5 parts by weight, polyphenylene ether MGC OPE-2ST: 18 parts by weight, rubber component KRATON GRP6935: 11.5 parts by weight, Tuftec M1913: 4. 5 parts by weight, Tuftec H1041: 4.5 parts by weight, phosphorus-nitrogen flame retardant SPB-100: 2.5 parts by weight, and average particle size: 0.5 μm spherical silica SO-C2: 25.0 parts by weight, Thermosetting resin EOCN-1020-65: 2.5 parts by weight, silane coupling agent A-1289: 0.5 parts by weight and xylene as a solvent: 132 parts by weight. After stirring, reaction initiator perbutyl P: 0.5 part by weight and curing catalyst Tuftec H1053: 4.5 part by weight, 2E4MZ: 0.05 were added to prepare an adhesive resin composition solution.
The adhesive resin composition solution was cast on a table on which a polyethylene terephthalate resin (PET) sheet was attached to obtain a film. The obtained film was dried at 80 ° C. for 10 minutes in an inert oven in which nitrogen gas was passed. The obtained film had a thickness of about 50 μm, had no stickiness, and was excellent in film formability.
This film was sandwiched between a polyimide film (Kapton EN25 μm manufactured by DuPont) and an FR-4 substrate etched out of copper foil, and thermally cured at 180 ° C. for 1 hour in a vacuum press molding machine to obtain a laminate.
As a result of testing for the peel strength of the polyimide film of this laminate, the tensile elongation at break was 21.2%, and the peel strength of the polyimide film was 1.02 (kN / m).

  4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 209 g (1.8 mol) of butyl acetate, 2771 g (16.5 mol) of phenol, toluene 11956 g was put into a 30 L reactor, 8 g of diethyl ether complex of boron trifluoride was added at 70 ° C., and reacted for 2.5 hours. After the polymerization solution was stopped with 26.7 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a polymer. The obtained polymer was washed with n-hexane, filtered, dried and weighed to obtain 2606 g of copolymer B (yield: 46.8 wt%).

Mn of the obtained copolymer B was 1940, Mw was 5640, and Mw / Mn was 2.91. By performing ¹³ C-NMR and ¹ H-NMR analysis, the copolymer B was observed to have a resonance line derived from the phenol end. As a result of conducting an elemental analysis result of the copolymer B, it was C: 85.8 wt%, H: 7.2 wt%, and O: 4.7 wt%. The introduction amount (a) of phenolic hydroxyl groups in the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 4.0 (pieces / molecule). Further, 71.8 mol% of the structural units derived from divinylbenzene and 28.2 mol% of the structural units derived from styrene and ethylbenzene were contained. The vinyl group content contained in the copolymer B was 36 mol%. As a result of TMA measurement, Tg was 272 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 1.5 wt%, and the heat discoloration was A. The result of measuring the total light transmittance with a turbidimeter was 88%. Copolymer B was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed.

Polyfunctional vinyl aromatic copolymer B obtained in Example 2: 8.0 parts by weight, GMA-modified E-MA copolymer LOTADA AX8900: 2.0 parts by weight and toluene: 150 parts by weight as a solvent Then, after stirring, a reaction initiator perbutyl P: 1.0 part by weight and triphenylphosphine TPP: 0.1 part by weight were added to prepare a resin composition solution for an adhesive.
Thereafter, a laminate was prepared in the same manner as in Example 1, and tested for tensile elongation at break and peel strength of the polyimide film of the laminate. As a result, the tensile elongation at break was 97%, and the peel strength of the polyimide film was 0.92 (kN / m).

  4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 155 g (1.8 mol) of butyl acetate, 4581 g (37.5 mol) of 2,6-xylenol Mol) and 12832 g of toluene were put into a 30 L reactor, and 13.7 g of diethyl ether complex of boron trifluoride was added at 80 ° C. and reacted for 4 hours. After the polymerization solution was stopped with 40.1 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a polymer. The obtained polymer was washed with n-hexane, filtered, dried and weighed to obtain 4979 g of copolymer D (yield: 89.4 wt%).

Mn of the obtained copolymer D was 1100, Mw was 2300, and Mw / Mn was 2.10. By performing ¹³ C-NMR and ¹ H-NMR analyses, resonance lines derived from the 2,6-xylenol end of copolymer A were observed. As a result of conducting the elemental analysis result of the copolymer D, they were C: 85.0 wt%, H: 7.9 wt%, and O: 5.3 wt%. The introduction amount (a) of the phenolic hydroxyl group of the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis result and the number average molecular weight in terms of standard polystyrene was 3.6 (pieces / molecule). Moreover, 78.1 mol% of structural units derived from divinylbenzene and 21.9 mol% in total of structural units derived from styrene and ethylbenzene were contained. The vinyl group content contained in the copolymer D was 26 mol%. As a result of the TMA measurement, Tg was 275 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 1.9 wt%, and the heat discoloration resistance was A. Copolymer D was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was observed.

  A resin composition solution for an adhesive was prepared in the same manner as in Example 1 except that the polyfunctional vinyl aromatic copolymer D obtained in Example 3 was used, and a laminate was produced. The peel strength of the polyimide film was tested. As a result, the tensile elongation at break was 7.7%, and the peel strength of the polyimide film was 0.73 (kN / m). It was.

  4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 209 g (1.8 mol) of butyl acetate, 317.3 g (1.90 mol) of phenol 11956 g of toluene was put into a 30 L reactor, 8 g of diethyl ether complex of boron trifluoride was added at 70 ° C., and the mixture was reacted for 3.25 hours. After the polymerization solution was stopped with 26.7 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a polymer. The obtained polymer was washed with n-hexane, filtered, dried, and weighed to obtain 1610 g of copolymer E (yield: 28.9 wt%).

Mn of the obtained copolymer E was 1980, Mw was 5630, and Mw / Mn was 2.69. By performing ¹³ C-NMR and ¹ H-NMR analyses, it was observed that the copolymer E had resonance lines derived from the phenol end. As a result of conducting the elemental analysis result of the copolymer E, it was C: 90.4 wt%, H: 8.3 wt%, and O: 1.1 wt%. The introduction amount (a) of phenolic hydroxyl groups in the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 1.2 (pieces / molecule). Further, 72.1 mol% of the structural units derived from divinylbenzene and 27.9 mol% in total of the structural units derived from styrene and ethylbenzene were contained. The vinyl group content contained in the copolymer E was 41 mol%. As a result of TMA measurement, Tg was 273 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 2.3 wt%, and the heat discoloration resistance was A. The result of measuring the total light transmittance with a turbidimeter was 83%. Copolymer E was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was observed.

Polyfunctional vinyl aromatic copolymer E obtained in Example 4: 8.0 parts by weight, GMA-modified E-MA copolymer LOTADA AX8900: 2.0 parts by weight and toluene: 150 parts by weight as a solvent Then, after stirring, a reaction initiator perbutyl P: 1.0 part by weight and triphenylphosphine TPP: 0.1 part by weight were added to prepare a resin composition solution for an adhesive.
Thereafter, a laminate was prepared in the same manner as in Example 1, and tested for tensile elongation at break and peel strength of the polyimide film of the laminate. As a result, the tensile elongation at break was 28%, and the peel strength of the polyimide film was 0.58 (kN / m).

  4230 g (32.4 mol) of divinylbenzene, 169 g (1.35 mol) of ethyl vinylbenzene, 1170 g (11.3 mol) of styrene, 209 g (1.8 mol) of butyl acetate, 138.6 g (0.83 mol) of phenol 11956 g of toluene was put into a 30 L reactor, 8 g of diethyl ether complex of boron trifluoride was added at 70 ° C., and the mixture was reacted for 3.25 hours. After the polymerization solution was stopped with 26.7 g of 1-butanol, the reaction mixture was poured into a large amount of n-hexane at room temperature to precipitate a polymer. The obtained polymer was washed with n-hexane, filtered, dried and weighed to obtain 1459 g of copolymer F (yield: 26.2 wt%).

Mn of the obtained copolymer F was 2010, Mw was 5710, and Mw / Mn was 2.97. By performing ¹³ C-NMR and ¹ H-NMR analysis, the copolymer F was observed to have a resonance line derived from the phenol end. The results of elemental analysis of copolymer F were C: 91.02 wt%, H: 8.0 wt%, and O: 0.96 wt%. The introduction amount (a) of phenolic hydroxyl groups in the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 0.7 (pieces / molecule). Moreover, 72.6 mol% of structural units derived from divinylbenzene and 27.4 mol% in total of structural units derived from styrene and ethylbenzene were contained. The vinyl group content contained in the copolymer F was 42 mol%.
As a result of TMA measurement, Tg was 273 ° C. and softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 2.4 wt%, and the heat discoloration resistance was A. The result of measuring the total light transmittance with a turbidimeter was 70%. Copolymer F was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was formed.

Polyfunctional vinyl aromatic copolymer F obtained in Example 5: 8.0 parts by weight, GMA modified E-MA copolymer LOTADA AX8900: 2.0 parts by weight and toluene: 150 parts by weight as a solvent Then, after stirring, a reaction initiator perbutyl P: 1.0 part by weight and triphenylphosphine TPP: 0.1 part by weight were added to prepare a resin composition solution for an adhesive.
Thereafter, a laminate was prepared in the same manner as in Example 1, and tested for tensile elongation at break and peel strength of the polyimide film of the laminate. As a result, the tensile elongation at break was 14%, and the peel strength of the polyimide film was 0.49 (kN / m).

Comparative Example 1
28.2 g (0.216 mol) of divinylbenzene, 1.1 g (9 mmol) of ethylvinylbenzene, 7.8 g (0.075 mol) of styrene, 1-chloroethylbenzene (12.0 mmol) in dichloroethane (0.634 mmol) / mL) 23.8 g, 4.2 g of dichloroethane solution (0.135 mmol / mL) of n-tetrabutylammonium bromide (0.45 mmol) and 189 g of dichloroethane (dielectric constant: 10.3) were put into a 300 mL flask. Then, 8.3 g of a dichloroethane solution (0.068 mmol / mL) of 0.45 mmol of SnCl ₄ was added at 70 ° C. and reacted for 1 hour. After the polymerization reaction was stopped with a small amount of methanol bubbled with nitrogen, the reaction mixture was poured into a large amount of methanol at room temperature to precipitate a polymer. The obtained polymer was washed with methanol, filtered, dried and weighed to obtain 7.07 g of copolymer R (yield: 27.1 wt%).

Mn of the obtained copolymer R was 2010, Mw was 2780, and Mw / Mn was 1.6. By performing ¹³ C-NMR and ¹ H-NMR analyses, the copolymer R has a structural unit derived from divinylbenzene of 76.6 mol%, a structural unit derived from ethylbenzene of 2.3 mol%, and a structural unit derived from styrene. The resonance line derived from the phenol end was not observed. As a result of conducting the elemental analysis result of the copolymer R, it was C: 86.8 wt%, H: 7.4 wt%, O: 0.3 wt%, Cl: 5.06 wt%. The amount of chlorine introduced into the terminal of the soluble polyfunctional vinyl aromatic polymer calculated from the elemental analysis results and the number average molecular weight in terms of standard polystyrene was 3.8 (pieces / molecule). As a result of the TMA measurement, Tg was 290 ° C., and the softening temperature was 300 ° C. or higher. As a result of TGA measurement, the weight loss at 300 ° C. was 12.1 wt%, and the heat discoloration resistance was x. The result of measuring the total light transmittance with a turbidimeter was 52%. Copolymer R was soluble in toluene, xylene, THF, dichloroethane, dichloromethane, and chloroform, and no gel was observed.

  Except that the polyfunctional vinyl aromatic copolymer R obtained in Comparative Example 1 was used, a resin composition solution for an adhesive was prepared in the same manner as in Example 1, a laminate was produced, and tensile elongation at break was produced. The laminate film was tested for the peel strength of the polyimide film. As a result, the tensile elongation at break was 7%, and the peel strength of the polyimide film was 0.30 (kN / m).

Explanatory drawing of branched structure of polyfunctional vinyl aromatic copolymer

Claims (7)

A copolymer obtained by copolymerizing 20 to 99 mol% of a divinyl aromatic compound (a) and 80 to 1 mol% of a monovinyl aromatic compound (b), wherein a polymerization additive (c The following formula (a1) having a phenolic hydroxyl group derived from) and derived from the divinyl aromatic compound (a)

(In the formula, R ¹ represents an aromatic hydrocarbon group having 6 to 30 carbon atoms.) The content of the structural unit containing an unreacted vinyl group is 10 to 90 mol%. A soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal which is soluble in toluene, xylene, tetrahydrofuran, dichloroethane or chloroform .   The number average molecular weight Mn is 500 to 100,000, and the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight Mw to the number average molecular weight Mn is 10.0 or less. A soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the end thereof.   3. The soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal according to claim 1, wherein the introduction amount (a1) of the phenolic hydroxyl group to the terminal is 2.2 / molecule or more. Coalescence. (A) Lewis acid catalyst (B) One or more promoters selected from ester compounds (C) In the presence of one or more polymerization additives selected from phenolic compounds, divinyl aromatic compounds are added in an amount of 20 to 99 mol% and A monomer component containing 80 to 1 mol% of a monovinyl aromatic compound is polymerized at a temperature of 20 to 120 ° C. in a homogeneous solvent dissolved in a solvent having a dielectric constant of 2.0 to 15.0. The method for producing a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at a terminal according to any one of claims 1 to 3.   The method for producing a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at a terminal according to claim 4, wherein the Lewis acid catalyst is a metal fluoride or a complex thereof.   The soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal according to claim 4 or 5, wherein the promoter is one or more ester compounds selected from the group consisting of ethyl acetate, propyl acetate and butyl acetate. Manufacturing method.   The polymerization additive is a phenolic compound having one or more phenolic hydroxyl groups selected from the group consisting of phenol, alkylphenol, dialkylphenol, phenylphenol, alkylphenylphenol, naphthol and alkylnaphthol. A process for producing a soluble polyfunctional vinyl aromatic copolymer having a phenolic hydroxyl group at the terminal.

Images